1. Field of the Invention
The present invention relates generally to a well apparatus for reeving flexible tubing into and out of a well bore and, more specifically to an apparatus for raising and lowering of a submersible pump from a well bore where the pump is run on a length of flexible tubing.
2. Description of the Prior Art
Modern water wells are drilled into the ground with the well bore either being uncased, or being protected by a casing which is sunk into the well. Typically, a submersible pump is then run down the well bore on flexible tubing and submerged in water located at the bottom of the well. The pump provides water to the surface through the flexible tubing which is connected to the pump and which leads up the well bore to the well surface. Although various types of flexible tubing are known, the most commonly used tubing today is a polyolefin, such as polyethylene. In certain of the prior art practices, a separate safety rope or cable is also provided, connected to the pump and extending the length of the bore to assist in withdrawal of the submersible pump from the well bore if the pipe were to separate or break. In addition, since the submersible pump is electrically driven, a power cord or cable also typically extends from the well surface down the bore to the pump where it is attached to the flexible tubing, as by taping the cable to the tubing.
In wells which have submersible pumps for pumping water up through long flexible plastic tubing of the type which has been described (hereafter “well flexible tubing”), tubing installation and removal has tended to be a difficult operation since these procedures are labor intensive and time consuming. A “Pump Setting Rig” or tower crane can be employed, but these solutions are expensive and involve relatively complicated pieces of equipment. These solutions may also be less than optimum because they do not allow the devices to be easily transported from one well location to another to service a plurality of different wells.
There are various reasons why it is necessary to pull the well tubing from the well bore. On occasion, it is necessary to access the submersible pump, either for servicing or replacement, or because the pump must be relocated at a different elevation in the well bore. In the past, when removal of the submersible pump was necessary, often the pump had to be physically removed from the well bore as by raising the pump by the flexible water pipe or tubing. Since well bores can be hundreds of feet deep, this results in hundreds of feet of length of the flexible water pipe and associated electrical wiring which must be accommodated. In the past, the tubing and associated electrical wiring were sometimes simply laid on the ground. This was not a satisfactory solution, however, since this practice is unsanitary and can lead to contamination of the well when the pump, electrical wiring and safety rope are returned to the well bore.
Removal of submersible pumps, as well as the removal of other types of well production and servicing devices, such as coiled tubing, has previously been accomplished by a variety of methods. In more shallow wells, where the weight of the pump and the flexible water pipe tubing is relatively small, physical manual hoisting of the pump and pipe has sometimes been used.
In addition, various mechanical devices have been developed over the years for removing submersible pumps and for removing other types of well devices. For example, U.S. Pat. No. 6,502,641 to Carriere, et al. shows a coiled tubing rig which includes a frame, a tiltable mast and an injector reel. The mast can be tilted to a position that aligns the coiled tubing with the BOP. However, this device is not used as a device for pulling a submersible pump from a well.
U.S. Pat. No. 4,188,997 is an early patent showing a well pump service apparatus. This patent attempts to align the cable with the well bore by means of a permanent well sheave 16 which is supported by frame members 26. It also appears to be a fixed type installation.
U.S. Pat. No. 5,848,641 shows a well pump puller. Although this reference shows a cylindrical drum 12 and a companion guide 82, it does not appear that the cylindrical drum pivots from the horizontal to a vertical position.
U.S. Pat. No. 3,589,642 shows a device for controlling the fleet angle of a cable being spooled onto a drum. It uses a mast 14 for guiding a well logging apparatus such as the sonde being lowered and raised from a well bore.
U.S. Pat. No. 3,116,781 shows a well workover apparatus including a cylindrical drum 12 and a yoke mechanism 18.
U.S. Pat. No. 3,991,978 shows a submersible pump boom which can be used for pulling or replacing a submersible pump.
U.S. Pat. No. 4,986,351 shows a device used for pump removal which includes a collar which is secured to the upper end of a well casing.
U.S. Pat. No. 4,523,645 shows an apparatus for removing reeved material from a wellbore such as a cable, electrical line or fluid conductor.
U.S. Pat. No. 4,296,916 shows another type of device for pulling submersible pumps from a well bore.
U.S. Pat. No. 4,673,035 is another apparatus which deals with a coil tubing operation. This reference does appear to show a cylindrical drum (25 in FIG. 1) which may be elevated to allow the operation of the apparatus with elevated well heads.
U.S. Pat. No. 5,996,971 shows another type of well pipe hoist which is secured to the well casing at the top of the well.
While the above references, and others, show a variety of device which have been used in the past for raising and lowering flexible tubing from a well bore, a need continues to exist for an improved submersible pump puller which is simple in design and economical to manufacture.
A need also exists for such a device which can be portably mounted for transport from one well location to another.
A need also exists for such an apparatus which evenly centers the vertical axis of the flexible tubing being fed into the well bore over the central vertical axis of the bore hole, so that contact between the flexible tubing and the sides or upper lip regions of the well casing is largely avoided.